Great Slave Lake at Hay River Water Level
Live river level, flow, historical records and forecast for Great Slave Lake at Hay River in NT, Canada, built from official government gauge data.
- Location NT, Canada
- Watershed lower hay
- Primary gauge 07OB002 (Water Survey of Canada)
About Great Slave Lake at Hay River
Great Slave Lake is a gauged lake in the Lower Hay watershed, Northwest Territories.
Season by season
This lake’s year is shaped by a short, sharp open-water season and a long winter floor. The typical high point is in June at 156.79 m (514.39 ft), while the typical low point is in November at 156.47 m (513.34 ft). That is a typical annual swing of 32.1 cm (12.6 in), so docks, shore access, and pump intakes need to handle a modest but real rise and fall through the season.
The record high was 157.76 m (517.57 ft) in May 2021. The record low was 155.97 m (511.72 ft) in November 2023. Those two marks show that this reach can move well beyond its typical band, and the spread matters if you are watching for waterline changes at the shore.
Records and rises
There are 42 years on record here, which gives the monthly pattern some weight. June has tended to hold the highest typical level, and November the lowest. That matches the broad subarctic rhythm: snowmelt and breakup set the spring rise, while winter tends to hold water lower and steadier.
For people on the lake, the practical point is timing. The highest water usually comes early in the open-water season, not at midsummer, so spring is when low-lying shoreline areas are most likely to be tested. By contrast, November is the month to watch for the lowest typical levels.
The station drains 956300 km2 (369229 sq mi) upstream of the gauge. That is a large contributing area, so changes arriving here reflect conditions across a wide reach rather than only the shoreline in front of you.
Reading the hero number
The number on the page is most useful when set beside the median for this calendar day, not just as a single elevation on its own. A current reading above or below that daily median tells you whether the lake is running high or low for the date, which is more useful for daily decisions than the raw number alone.
This station has more than 42 years of record, so that calendar-day median comes from a meaningful local history. The operating agency is Water Survey of Canada.
How this page is built
Readings come from official government gauges and are rolled into daily records: the daily mean, high and low for every day on record. Each calendar day gets its own baseline from the full history, so the level you see is compared against what this specific date usually looks like rather than an annual average.
How Nibi Metrics works · Water stories
Nibi Metrics - live water levels, flow, and forecasts for lakes and rivers across Canada, the US and the UK
Real-time water levels, forecasts, and alerts for lakes and rivers across Canada, the US and the UK. Built on official government data.
Nibi Metrics tracks more than 13,000 gauged lakes and rivers across Canada, the United States and the United Kingdom, reading directly from official federal monitoring networks: the Water Survey of Canada, the United States Geological Survey, Quebec's provincial hydrometric network, and the Environment Agency for England. Every number on the platform is measured, not modelled - taken from a government gauge on the water itself and compared against that location's own historical record for this exact date.
What you can see for any monitored lake or river
The level right now, in feet or metres, updated as the source agency publishes new readings - for many stations that is every five to fifteen minutes. How today compares to typical: every location carries its own typical-for-this-date band built from its historical record, so a reading is never just a number - it is above, below, or near what this water usually does on this calendar day. Which way it is moving: a measured RISING, FALLING, or STEADY verdict computed from the gauge's own recent readings, with the rate of change - the difference between a flood ending and one beginning. What comes next: level forecasts up to 72 hours ahead, driven by the gauge's recent behaviour, upstream water, and quantitative precipitation forecasts, alongside live radar, lightning, and weather for the surrounding region.
Alerts that watch the water for you
Set a threshold on any location - a level, a distance above typical, or a rate of climb - and Nibi emails or notifies you the moment the gauge crosses it. Cottagers use it for spring freshet, anglers for river conditions, marinas and municipalities for operations. The scanning runs around the clock against the same measured data shown on every page.
Where Nibi comes from
Nibi means water in Anishinaabemowin. The platform began at a family cottage on Lake Muskoka, Ontario, where the spring melt floods the shoreline most years and the only forecast was standing on the dock, looking, and guessing. It grew into an independent, member-funded platform run by Muskoka Research Inc. - no investors, no data resale, and a privacy policy shorter than most cookie banners. The core data is free for everyone, forever; paid plans add automation like multi-location alerts, deep history, and reports.
Coverage
Nibi spans the continent: every Canadian province and territory with active federal gauges - from Vancouver Island rivers to the Muskoka lakes, prairie reservoirs, and Quebec's hydrometric network - and the United States from Maine to the Texas Hill Country, the Ohio Valley, and the Pacific Northwest. Coverage grows where the water news is: when a basin floods, its gauges join the platform with their full historical records attached. Many stations report every five to fifteen minutes; most report at least hourly; every page states exactly when its gauge last spoke.
Free forever, funded by members
The core promise is simple: the water data is free, for everyone, forever. Live levels, maps, radar, and recent history never sit behind a paywall. Paid plans fund the platform by adding automation - multi-location alerts, decades of history, longer forecasts, and PDF reports - so the people who need more carry the cost for everyone who just needs to check the lake before driving up. There are no investors and no advertising deals shaping what the data says.
Water Stories
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Inside the freshet cycle that puts Manitoba shorelines at risk each year - and why 2026 broke the script.
The science of snow water equivalent and why it drives the season ahead.
What the numbers on the measuring stick actually tell you.
Why Central and South Texas rivers go from gravel beds to fifty-year records in an afternoon - including July 2026 on the Nueces.
One percent, every year, forever - unwrapping hydrology's most misunderstood phrase, and how it differs from our own percentiles.
How every number is computed - About the platform
